If Statements

Conditional statements control which code blocks execute based on boolean conditions. Python uses if, elif, and else with indentation-based blocks — no parentheses or curly braces needed.

Syntax & Patterns

• if condition: — executes when condition is truthy
• elif: — else-if, checked sequentially after the first if
• else: — fallback when no conditions are met
• Ternary expression: value_if_true if condition else value_if_false
• Chained comparisons: if 0 < x < 10:

Best Practices

• Prefer early returns (guard clauses) over deeply nested if-else blocks
• Use truthiness: if items: instead of if len(items) > 0:
• Use is None for None checks, not == None
• Consider match/case (Python 3.10+) for complex branching